Article

California's wine caves

Mar./Apr. 2011 California Country magazine
Story by Kate CampbellPhotos by Daniel D'Agostini and Florence Low

Secret treasures, hidden pleasures

The wine caves at Sonoma County's Bella Vineyards, completed in 2003, allowed the winery to expand its storage capacity without having to take out vines to build an aboveground structure.

Caves are places of wonder, of shelter and security, and dwelling inside them is a tradition as old as the human race. Although evidence shows these hidden structures also were used exclusively to store wine as far back as 6,100 years ago, California's winegrape growers and wineries now are building new kinds of wine caves and using them in ways never before seen.

In addition to providing efficient storage and aging facilities, which the state's first wineries took advantage of as early as the 1870s, today's underground spaces are carefully designed for multiple uses, such as tasting rooms, retail shops and offices. Wine caves also provide settings for special events like dinners, receptions and musical performances.

In 2009, Daniel D'Agostini, co-author and photographer of "Into the Earth: A Wine Cave Renaissance," counted about 150 publicly accessible wine caves and another 50 private caves in California, almost all built in recent decades.

Daniel D'Agostini says new technology and a new way of thinking about these ancient underground structures have sparked a renaissance in modern wine cave building.

"Using caves for wine storage is more popular now than at any time in the state's history," said D'Agostini, who adds farming and teaching to his skills as author and photographer. "We're seeing this renaissance in the use of caves in large part because they help preserve the natural landscape above ground, while providing versatile commercial space that also appeals to visitors."

Caves and tunnels, which help reduce energy use through their naturally constant temperature of about 60 degrees Fahrenheit, are not only perfect for aging wine, they also reduce evaporation loss in the barrels because of naturally high humidity levels.

Stephen Kautz says creating the wine caves was the first step in building the Ironstone Winery and destination venue in the Sierra Nevada foothills near Murphys. In addition to storing wine, the caves are used for dining and special events.

Although the economy has been down in recent years and cave building has slowed, D'Agostini said, "there are two under way near me (Shenandoah Valley, Amador County) and a third in the wings. There's at least one being built in Paso Robles, maybe two.

Attractive landscaping and a graceful portal lead to Rutherford Hill Winery's 40,000-square-foot underground storage space. Beringer Vineyards, with some of the nation's oldest wine caves, restored them in 1972 and added features like a tasting library to the space.

"From talking to the people building them, it sounds like things are picking up a bit," he added. "And new wine caves also have been constructed in other states—Oregon, Washington, Virginia—and in countries such as Argentina, Chile, New Zealand, Australia, Spain and Italy."

Underground facilities, whether cut and covered structures or bored and blasted caves, are routinely being considered for inclusion when a new winery is designed or one is renovated. D'Agostini said caves are a real help for those farmers and wine producers aiming for green efficiency ratings that recognize building and development practices that reduce environmental impacts.

Steven Kautz, president of Kautz Family Vineyards, with a winery and vineyards in the Sierra Nevada foothills of Calaveras County, said his family grows winegrapes on land rich in Gold Rush history.

Napa Valley architect Jon Lail says he has long believed in the value of subterranean wine storage because of the environmental benefits.

"When we started looking at our land in the 1980s, we recognized that we had about 100 open mine shafts and tunnels that the '49ers left behind," Kautz said. "We looked at these original underground structures as potential wine-aging and storage facilities for our new Ironstone Winery. We finally decided they couldn't be used for that purpose."

A geologist doing survey work on the shafts and tunnels, however, pointed out that the ranch also included a solid-rock mountain. The formation wasn't good for growing crops or raising cattle.

"After much talk, we decided to create our wine caverns there," Kautz explained. "Then over the top of the caves, we built a rustic seven-story winery structure designed in the style of an old stamp mill like the ones used to crush quartz ore and separate the gold."

The family formed its own mining company and blasted, picked and shoveled its way into 10,000 square feet of rock to create wine caverns. Now, each year's vintage is stored and aged in oak barrels racked four high, and, as the wine is bottled, space is created for dining and celebrations.

But not all wine caves are blasted into the earth like Ironstone's; others are designed by architects and excavated with heavy equipment. (See story below for more about construction techniques.)

Although the Kautz family is among the first to build modern wine caves in California, Beringer Vineyards, established in 1876 in the Napa Valley, still uses the original hand-dug caverns to age and store wine. The winery's two tunnels, each 400 feet long, were restored and strengthened in 1972. Several shorter tunnels branch off the long tunnels to create more than 13,000 square feet of underground storage space.

While the historic Beringer wine tunnels were being restored, grapevines were being planted a few miles away for what would become Rutherford Hill Winery. In 1984, the company began construction on a modern cavern complex that accommodates aging barrels. A second underground project added connecting tunnels, a back cave and dining grotto for special events.

Above the Napa Valley on Howell Mountain, Randy and Lori Dunn hold sumptuous dinners in their wine caves at Dunn Vineyards. These caves were among the last created in California during the 1980s.

Napa Valley architect Jon Lail, a leader in the design and construction of wine caves, said the subsurface structures are the "most environmentally responsible way to store wine, both in barrel and in bottle."

Dunn Vineyards, on Howell Mountain above the Napa Valley, outgrew its existing winery, so in 1989 its wine caves were completed to add space for barrel storage. The caves also are an enchanting space for private dinners.

At Rutherford's private Sloan Estate, where grapes produce wines that sell for $200 to $300 a bottle, owner Stuart Sloan worked with St. Helena-based engineering expert Alf Burtleson beginning in 2000 to mine out a 700-foot tunnel that runs laser-straight under the estate's gardens, tennis courts and the family home.

The winery is not open to the public, but Martha McClellan, Sloan Estate winemaker, said the cavern's bricked arches and dramatic lighting are "indeed beautiful.... The cave's purpose is to provide a tranquil, peace-filled atmosphere for the wine to rest and age for two or more years. In the end, this beauty contributes to the soul of the wine, nurtured from vine, to tank, to barrel and ultimately to bottle."

Modern cave building

Building wine caves in California has become a sophisticated construction specialty employing the disciplines of architecture, engineering and mining. Looking like a giant medieval weapon, a roadheader, above, is used to rip through rock while shotcrete, a liquid concrete, is sprayed, below, to stabilize cave interiors.

Although man-made caves were dug in the state's early days, cave construction projects took off in the 1970s due to wineries' demand for more storage space and the need to protect agricultural land for planting. At the same time, better excavating techniques and equipment made building underground easier.

These subterranean structures range in size from a few thousand square feet to more than 50,000 square feet. Some are simple bores into hillsides; others are more elaborate. Though the caves share the common function of aging and storing wines, each cave and tunnel is unique.

Today, builders with geology reports and permits—and perhaps a license to explode dynamite—create these underground spaces at carefully selected sites.

Excavation is often done using a roadheader or a milling head. A heavy-duty roadheader weighs more than 30 tons and has an extending boom with a rotating head. The "teeth" on these rotating heads can exert thousands of pounds of pressure per square inch, enough to crack rock and shape huge caverns at a rate of 2 feet to 15 feet a day, depending on geologic conditions.

"When we're excavating new ground, there's a wonderful sense of discovery, of being where no one else has ever been," said civil engineer Vincent Georges, owner of The Cave Company in Napa. "I feel lucky to be able to contribute to the romance that is a well-crafted wine."

As it's hollowed out, the internal structure of the wine cave is reinforced with steel and shotcrete (a fluid form of concrete) that's sprayed onto the structure with high-pressure "guns."

Welded wire fabric also may be installed to ensure stability, as well as bolting and bracing systems. Prefabricated drainage strips are usually installed at regular intervals between the natural walls and the shotcrete liners to channel naturally occurring moisture.

Experts note that California mining companies are at the forefront of cave engineering and construction, adding to the understanding of advanced waterproofing technology as applied underground. By the time a wine cave is completed, which can take six months to two years, depending on size and geology, shotcrete sprayed on the interior walls may be as much as 4 to 8 inches thick.

Where to tour wine caves

This is a selected list of publicly accessible wine caves in California. There are more under construction. Please call or check websites for current hours and availability.